Tuning fork piano



Nov. 18, 1941. D. SEBOUH TUNING FORK PIANO Filed Feb. 3, 1940 2 Sheets-Sheet l MID mi: 5 @WW 1941- D. SEBOUH 2,263,106

TUNING FORK PIANO Filed Feb. 3, 1940' 2 Sheets-Sheet 2 Patented Nov. 18, 1941 i men-in s'poua -Ne r m-N. a; v i lmeli p fsbrum 3, 49 6. 317th?!) .Myl v nt onr latestoa-plan tand m par: fitted heWeenand-in contact with the free ends cu a y. to; piano which en ploys tuning i'orks Qisthe prongs; t0.;movefrom the .fork and reas,-' tr'ibration prod m h d-;prodneing;- mainzoutofgcontact -with'its prongs allowing the agents and legtricalamplifications:zIlhese eleel latterrtoyvibrate"freely. 'As soon-as'the key I meats. take :the place; of str'lngs-.1and=soundlne: '5 isreleased the spring librings the damper head board respecti vel y-. of .theoonv entional Pia o- 1 2 6- .back.= to; iis;original:- position against the prongs The. elimination of -the' sounding board, thepiatm: and the vibration: ceases? The fixed and desired thebridges and the strings, andtheintroductiom IDOSiUQItg-znbthe under-lever:l2.- and the spoon HI of -tnni'ngjorks ands. 1ept, rj, 1- -ampliflcation11114.2 in relation-to the damper lever "I is effected thru h Pla e;makesitpossibleto-makeapiano thalim regulating :the .hook'lfi 'to 'the proper height. is small-gin dimensionsatgthe-wsamei The :straizhte'nd of' this hook is threaded and timea pur fa a; rr 1. t gxtheaualit mnm "scregstotho-unaerslever: l2. The hooked end the pitch-o which isnpt afieotedabymhangesiin: is; supported sbythehook-ralil l1. Because of temperature or.;by othercauses illratingtoah thisssuppo'rt of the under-lever 12 by the hookfbt the p whg nlithe- 9l1& I15tandard;p1aBOS;:i- I'EllffiyllgitfilS :also possible tomove the entire Myi-mproyedv plane will notrequireztuning. damperaction=assembly-out of and into the The;. f ollowing isthedescription,obther-invenar piano withoutwdisturbing the damper action in iQ -QB is en s seh s ut-he;.accompanyinsw any-way: drawin iv 'minz a; ;partor th s-.specificatiom sine .zhook-rail whereinJikemumQ als vofreference indicate ioor o bracket:.'|5..and" threads thru all the'brackets'as responding .parts;.tl 1r oug h;.-the seve;a1- -viewsa.in- .aishown." :-'1 he"hook-r'ailis"covred with felt where whichl-w- '1 itzcomes infcontaot with the hooks'li to insure Fig.1 -is the top} plan view-f the-scale pinion-.1; quiet action; The r-ail l4 holds various parts of notepiano emb d ng my invention; as; installed the action together andis also supported by the inaconventional;piano case. ,1 .s .actionbrackets 'II. Thel'ou'd pedalrod I8 is ,Fig. ;2 isasideeleyationalyiew'showing a=tun-' s,=-zinstalled a'nd functions e'ita'ctlythe same as in ing forkmountediin relationto-a hammer; actionatheupright piano'action. The damper wire l9 and-a damper action:useddmthe-scale:illustrated:-- isiasten'edto the damper-lever 1' and the length inFigQl and showing the-position 0t two :smaller of itshorizontal'section' is regulated by the set mounted; forks-in ;re lation-to;the:-1me-formed by ,scfewfl-H r the strikingpoints of the hammerstl- .1 I- The vertical section of the damper wires (l9,

3;is atcross-sectional'view of+the?mou'nting='- |9a,' l 9'b) :are 'a'll of'e'venle'ng'th except in the exrail showing themethod of mounting; tremebase section wher'e they are slightly longer Fig.4 is a-frontplan view of a'secti'orr'of he infiip'ropor't'ion -to'*thelarger base forks. In the mounting-rail.-.. w 5-12. 4 3 other 's'ections' (except the extreme base) the Referring now to the drawings: in Fig;=2-is"== .-widths of thefior'ks, taken from the line 2|-2l, shown thekey I and thehamm'er.actlonwt'of a Fig. 2',=arje even throughout the scale. The horistandard grand piano. ThG-d68.i15z0f this action zontal section of said wires however varies. The

H'is fastened to the action are omitted as they do not: concernazthisiinvenreason' i'or-this is-in the following explanation.

tion.- Ijri my improved pianov'the hammer action i order to produce a fundamental tone as and thekeys function exactly the same'ias they do gfree from undesired harmonies as possible the man-ordinary grandpiano- The hammer 3' here' hammer must 'strike'the fork at a certain strikstrikes the ,tuningfork Las'it-wouldtstrike the ing-point. (See the line SPJ in Figs. 1 and 2.) string in anordinary piano. .The damper meclia='-'-T The ilin'e formed-directly above the hammers by nisrnv howeverforms a part of. this invention; I

Theconstruction and the mechanism' ofsaid gmust naturally entendfin'parallelyspaced reladamperaction, resembles 'the standard upri'ghtf' tidnto'theline' lormedimdemeath by the tips damper action with'the exceptlonthat' here tli'e of 'all' the ii'a'r'rir'riers of the'action. The distance directionof ;.the;-,-motionis-contrary -to' that" or" betwenthestriking'point SP on the fork and the upright damper action. .The ciamper head @980 its'tree-ends isdirectly proportional to the entire thedamperjl ver "L he' mp r fis ik' aiength of-lts"prongs;'- -"Thestriking point conunderleverflange-S and the spool lfl are'essen-E sidered best is a position on'the prongs located t1a11y.- the .sameas usedinthestandard upright ata distance'fromthe'free ends of the fork action and serve similar-purposes. equivalent to onef-fourthof the prongs. The

'45 these" strikingpoir'itsof allthe forks of the scale When-the key' l is pressed dowr'if-to-makethe; longer the prongs mana er the distance behammer 3 to strike the fork'4,"=by*engag ing" the -'.twe'en"their='strikingpointand their free ends, capstan screw llita-lifts-up the undei-Llevei '12 ff andin consequence the longer the, horizontal which in turn; thriu the spoon I0 movestnesection of s' corresponding damper wire (l9, Ha, damperlelv'er I-.:forward at point marked M. l9b;-'Flg.-'2).-' "In"this connection it should also Th action causes h fl p wh ch is be stated here that this parallel spaced relation- 2 v ship between the line of striking points of the forks and the line of hammers. below is one of the factors determining the design of the entire scale, 1. e. the selection of the size of the forks,

Holes are bored thru' the mounting rail, Figs.

1, 3 and 4, on horizontal level and at right angles or nearly so to its length toreceive the stems 23 of the forks. The design of the scale determines the degree of the angle at which the mounting rail is set which setting in turn determines the exact angle of the borings. The spacing of the borings corresponds exactly to the spacing of the hammers on the hammer rail the action. Referring to Fig. 3,a cross-section in actual size of the mounting'rail 22 and the stem 23 set in plhce-the purpose of the rubber bushing 2 is to prevent the fork from vibrating bodily as a whole and producing another audible frequency in addition to the frequency of the prongs proper. In other words, if the hole housing the stem 23 was not hushed with rubber, felt or similar material and the said stem was fitted and set tight against the wood or metal walls of the hole, each time the prongs were struck, we would hear simultaneouslytwo tones of different pitches, vthe one corresponding to the frequency of the prongs proper and the other to the frequency of the en the fork vibrating bodily as a whole.

The bushing 25 serves the same purpose,i. e. also to prevent any solid connection between the stem 23 and the mounting rail 22 thru the set screw 28 the set screw rail or bar 28. The latter is fastened tight to the mounting rail" 22 as shown in Fig. 4. The second purpose of the bushing. 24, while gripping the" stem 23 firmly in place, ,is'to it 21 need a certainthickness to be effective and as the space for them is limited (Fig. 4) The set screw 28, after passing down thru the bushed hole of the set screw rail 26 and into the threaded hole in the collar 21, connects itself fast to the stem of the fork. Thus, once set, the fork cannot 7 move backward or forward and cannot frotate.

The fork is held in place firmly in the same manner as holding the stem with ones hands without having at the same time any solid or fast connection to the mounting rail.

prevent the dissipation of the energy 0! the vibraof my improved-upright piano are essentially the same as that of my grand piano described above, except that in the upright modification a standard upright piano action is used, which circumstance makes it necessary to mount the forks in a vertical position and the mounting rail, the speaking tube rail, etc., in a respectively changed position. Another exception is the damper action. This is similar to the damper actions used in the old square pianos and need not be described here as its mechanism is well known.

Having thus' concluded the description of my invention I claim:

1. A non-rigid mounting for tuning forks adapted for use in musical instruments which comprises a mounting rail, a plurality of apertures in said rail corresponding in number to the number of tuning forks to be mounted therein, a resilient bushing in each of said apertures adapted for snugly holding the stems of said tuning forks, and means for preventing longitudinal and angular displacement of said stems in the bushings, thereby providing a. resilient mounting for tuning forks to prevent vibration of said tuning forks bodily as a whole and to prevent thedissipation of energy of the vibrating prongs whereby a single tone can be produced corresponding to the frequency of the prongs and whereby said prongs can vibrate for a relatively long period,

2. A. non-rigid mounting for tuning forks which comprises a mounting rail, a plurality of apertures in said rail corresponding in number to the number of tuning forks to be mounted therein, a resilient bushing in each of saidapertures adapted for snugly holding the stems of said tuning forks, abar associated with said mounting rail, a plurality of orifices therein substantially perpendicular to the axes of the apertures in the mounting rail, a resilient bushing in eachof said orifices,-and a set screw snugly' whereby said prongs can vibrate for a relatively long period.

3. In a musical instrument comprising a frame, a plurality of tuning forks having prongs of varying size, meansfor separately striking the prongs Fig. 4 is the front view of a section of the mounting rail attached to the case at one end. It shows the relative connections'and positions of the set screw rail 26, set screw 28, collar 21. and the fork stems.

' The principles of construction and mechanism, mounting of the forks, the damping system, etc,

of said tuning forks to set up vibrations therein whereby sound waves are produced, means for damping said vibrations whereby production of sound waves is stopped, means adjacent the prongs for collecting said sound waves, a microphone for amplifying and reproducing said sound waves, and means for conveying the sound waves to said microphone, thereby providing reproduction of the sound waves in amplified form whereby a succession of musical notes can be produced, the improvement which comprises a mounting rail attached to said frame, a plurality of apertures in said rail corresponding in number to the number of tuning forks provided, "a-resil'ient bushing in each of said apertures adapted for snugly holding the stems of the tuning forks, mean 'for preventing longitudinal and angular displacement of said stems in said bushings whereby a nonrigid mounting for tuning forks is provided.

, DIC KRAN SEBOUH. 

